Display holders are used in many different places where it is desired to display information. For example, on building walls such as in car show rooms, and in supermarkets and other shops. The holders can also be placed on posts or on stands, for example on garage forecourts, and can be used in vehicles such as trains, buses, and taxi cabs. The display holders can be used both indoors and outdoors.
One requirement for these display holders is that they must be able to secure the display material firmly and securely and be robust. That is, the holders must be able to withstand movements, for example, from the motion of a train, from the wind or from casual handling. The display holders must also protect the display material from the weather and from any other dirt or dust in the environment as well as being weather-proof themselves.
Another requirement for the holders is that they must be easy and quick to assemble and to mount onto a support such as a wall or post. This is especially important for advertising displays where it is important to minimize the costs of assembling the frame and fixing the frame to a support in the desired location.
It is also necessary to be able to quickly and easily change or replace the display material in the holder, for example when new advertising material is being changed or updated. One problem with known display holders is that it may be difficult to do this. For example, the user needs to guard against getting his or her fingers trapped in the holder mechanism and must carefully hold the frame whilst replacing the display material.
Equally importantly, the moveable portion of a frame used to clip or hold the display portion in place, generally known as a retaining leaf, may get damaged in use and it then becomes necessary to replace it. Alternatively, different artwork may require a different color finish to the clip. In both these cases it is desirable to be able to replace the clip or retaining portion without dismantling the frame. This feature is not generally provided by prior art display holders.
Display holders are known per se. For example, U.S. Pat. No. 3,301,901 (Sarkisian) describes a two-part frame element with the two parts, a base portion and a clamping element, held under tension by a complex-shaped leaf spring. GB 2 005 535 (Marketing Displays Inc) describes an improvement to U.S. Pat. No. 3,301,901 in which the spring is replaced by a simple leaf spring. However, in neither case can the moveable clamping element be replaced without dismantling the entire frame.
Similarly U.S. Pat. No. 4,498,255 (Heard) and U.S. Pat. No. 4,702,025 (Mace) describe further variations on this two-part construction theme. In both cases the two components must be assembled by sliding the parts together along their respective longitudinal axes. This form of construction also precludes replacement once the frame has been assembled.
U.S. Pat. No. 5,396,722 (Oszrovsky) describes a frame element in which a base member a clip support member and a clip are either glued together or co-extruded Whilst this latter prior art provides a visually appealing "frame within a frame" appearance it is difficult to construct and repair. A two part frame is described in U.S. Pat. No. 5,364,057 (Pynenburg) which is the closest prior art known to the applicant. Another disadvantage with known display holders is that they are only capable of holding display material with a certain pre-determined thickness or range of thicknesses. This is problematic if it is desired to use display material that is formed on thick board as well as paper, for example. It may also be necessary to place an additional water-proof transparent cover over the display material and this can also increases the thickness of the display material.
The known display holders also require a back panel (for example, fluted polypropylene material) to the frame against which the display material is held. This back panel is problematic because it further limits the space which the display material can occupy and is an extra part which must be supplied and transported to the site. Furthermore, where the back panels are not retained by positive fixings this means that they can be lost in strong winds so rendering the frame useless. A further disadvantage is that in known display holders the user often traps his or her fingers between the movable part of the frame and the artwork. The frames typically close in a snap-action fashion which can be very rapid. Also there is a danger that the springs may pop-out of the display holder as the display material is being replaced. This can be very dangerous because the springs are sharp and may fly out of the display holder at some speed. Also, it is difficult to replace the springs into the display holder.
It is accordingly an object of the present invention to provide a display holder suitable for presenting posters and similar advertising material which overcomes or at least mitigates some or all of the problems noted above.